This is just a copy of what I had in a different discussion thing:

Ok, I think I've isolated the lsslider problem. It occurs when you change from a themeskin not using lsslider to a theme using lsslider.

Say you remove the volume box from the gathering skin. Then switching from stylish version to normal version, or to another theme will probably crash litestep. Then you have to forcibly terminate litestep and rerun it.

So now that I've readded the volume box to the gathering, it doesn't crash when I switch skins anymore.